Log In
Search suggestions

    My Vehicles

    2007 BMW 750LI 4.8L EFI DOHC 8cyl

    My Store

    405 N COLLEGE ST
    (479) 443-4043

    CLOSED Open at 7:30 AM

    SAVE 20% ON ONLINE SHIP-TO-HOME ORDERS OF $100 OR MORE.

    Use Code: SEECLEAR

    See Details

    Chrysler Front Wheel Drive Cars 4-CYL 1981-1995 Repair Information

    Idle Speed Control (ISC) Motor

    Print

    OPERATION



    Eagle Throttle Body Fuel Injection (TBI) System

    The Eagle TBI system is used only on 2.5L Premier engines.

    The Idle Speed Control (ISC) motor is mounted to the throttle body and controlled by the PCM. The throttle lever rests against the initial adjustment screw of the actuator (plunger). The idle speed is not adjustable. The initial adjustment screw is only used to establish the initial positioning of the actuator when the ISC motor has been replaced.

    The actuator extends or retracts to control engine idle speed and to set throttle stop angle during deceleration. Based on inputs from the various engine control system sensors and switches to the PCM supplies current to the ISC motor to adjust the actuator position for the particular operating conditions.

    TESTING



    Eagle Throttle Body Fuel Injection (TBI) System

    See Figure 1

    Click image to see an enlarged view

    Fig. Fig. 1: The ISC motor and closed throttle switch connector terminal identification and circuit wiring schematic

    1. Unplug the ISC motor electrical connector.
    2.  
    3. Modify the electrical connector of the ISC motor Exerciser Tool 7088 as follows so that it will connect to the ISC motor. Use a hobby knife to cut a groove in terminal A that is the same size and shape as the grooves in terminals B and D .
    4.  
    5. Connect the ISC motor Tester 7088 connector to the ISC motor.
    6.  
    7. Connect the tester to the battery: red clip to positive and black clip to negative.
    8.  
    9. Start the engine.
    10.  
    11. Place the tester's switch to the RETRACT position. Observe the ISC motor actuator and engine idle speed. The actuator should retract and engine idle speed should decrease.
      1. If the ISC motor actuator retracts and the idle speed decreases, proceed to Step 6.
      2.  
      3. If the ISC motor actuator does not retract, it is defective and should be replaced.
      4.  

    12.  
    13. Place the tester's switch in the EXTEND position. Observe the ISC motor actuator and engine idle speed again. The actuator should extend and engine idle speed should increase.
      1. If the ISC motor actuator extends and the engine idle speed increases, the ISC motor is OK. Have the vehicle's system tested by a qualified automotive technician.
      2.  
      3. If the ISC motor actuator does not extend, it is defective and should be replaced.
      4.  

    14.  

    REMOVAL & INSTALLATION



    Eagle Throttle Body Fuel Injection (TBI) System

    The ISC motor is located on the front side of the throttle body.

    1. Disconnect the negative battery cable.
    2.  
    3. Remove the air cleaner bonnet.
    4.  
    5. Remove the ISC motor mounting nuts.
    6.  
    7. Remove the ISC motor from the bracket.
    8.  
    9. Disengage the electrical connector from the motor.
    10.  

    To install:
    1. Attach the electrical connector to the ISC motor.
    2.  
    3. Position the ISC motor onto its mounting bracket.
    4.  
    5. Install and tighten the ISC motor mounting nuts until secure.
    6.  
    7. Install the air cleaner bonnet.
    8.  
    9. Adjust the ISC motor, as follows:
      1. Start the engine and allow it to warm up to normal operating temperature.
      2.  
      3. Turn the engine OFF .
      4.  
      5. Disconnect the ISC motor connector.
      6.  
      7. Modify the electrical connector of the ISC motor Exerciser Tool 7088 as follows so that it will connect to the ISC motor. Use a hobby knife to cut a groove in terminal A that is the same size and shape as the grooves in terminals B and D .
      8.  
      9. Connect the ISC motor Tester 7088 connector to the ISC motor.
      10.  
      11. Connect the tester to the battery: red clip to positive and black clip to negative.
      12.  
      13. Start the engine.
      14.  
      15. Place the tester's switch in the EXTEND position. The actuator (plunger) should extend.
      16.  
      17. Adjust the plunger screw until the engine is running at 3500 rpm.
      18.  
      19. Turn the engine OFF .
      20.  
      21. Remove Tool 7088 and attach the ISC motor electrical connector. Idle speed should automatically return to normal within a few seconds.
      22.  

    10.  

     
    AutoZone Logo